Modifications of proteoglycans extracted from monolayer cultures of young and senescent human skin fibroblasts.
Proteoglycans (PGs) were extracted from culture monolayers of human skin fibroblasts (HFs) at early and late passages. Total PGs from senescent cells had markedly reduced abilities to bind type I collagen and hyaluronic acid, but retained normal binding properties with fibronectin and laminin. The constituent polysaccharides of PGs were comparatively characterised. PGs recovered from young and senescent HF cultures had equivalent total polyanionic charges and similar size distributions of the glycosaminoglycan chains. This applied to both types of polysaccharide chains found in PGs, namely the galactosaminoglycuronans (GalN-GAGs) and the glucosaminoglycuronans (GlcN-GAGs). However, senescent HFs produced a greater proportion of PGs containing GlcN-GAG chains and increased the sulphation of the remaining PG fraction with GalN-GAG moieties, yielding a major gain of C6-sulphate groups in the galactosamine residues.
Passi
A
A
Department of Biochemistry A. Castellani, II Faculty of Medicine and Surgery, University of Pavia, Italy.
Albertini
R
R
Campagnari
F
F
De Luca
G
G
D000375:Aging / Q000502:physiology*; D002455:Cell Division / Q000502:physiology*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D003094:Collagen / Q000378:metabolism; D004187:Disaccharides / Q000032:analysis / Q000737:chemistry; D005347:Fibroblasts; D005353:Fibronectins / Q000378:metabolism; D005944:Glucosamine / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000378:metabolism; D007797:Laminin / Q000378:metabolism; D011485:Protein Binding; D011509:Proteoglycans / Q000032:analysis / Q000737:chemistry / Q000378:metabolism*; D013997:Time Factors
D004187:Disaccharides; D005353:Fibronectins; D007797:Laminin; D011509:Proteoglycans; D006820:Hyaluronic Acid; D003094:Collagen; D005944:Glucosamine